During routine conversations, the CEO of a new start-up reports that

20%

of adults between the ages of 21 and 39 will purchase her new product. Hearing this, some investors decide to conduct a large-scale study, hoping to estimate the proportion to within

6%

with

99%

confidence. How many randomly selected adults between the ages of 21 and 39 must they survey?

The number of adults that should be surveyed is

enter your response here.